Railway signaling



March 21, R A ANN RAILWAY SIGNALING Original Filed Sept. 25, 1951 INVENTOR.

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. wlmvw M 2 ATTORNEY.

Patented Mar. 21, 1933 UNITED STATES PATENTVOFFICE" RONALD A. MCCANN, 0F SWISSVAIJE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH 8a SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA RAILWAY SIGNALING Application filed September 25, 1931,. Serial No. 565,095. Renewed August 24:, 1932. I

My invention relates to railway signaling, and particularly to signaling for trafiic movements from different directions over the same stretch of track. V

One feature of my invention is the provision of means for inter-controlling the caution and proceed indications of opposing signals by apparatus requiring only three line wires.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the rails of a stretch Y of railway track over which traffic may move in either direction. The rails 1 and 1 are divided by means of insulated joints 2 into sections AB, BC, etc. Each of these track sections is provided with a track circuit includin a battery 3 connected across the .rails ad acent one end of the section, and. a

relay designated by the reference character R with a distinguishing exponent and connected across the rails adjacent the opposite end of the section.

A track repeater relay T is controlled by track relays R R R and R A second track repeater relay T 4 is controlled by track relays R R R and R Signals, designated by the reference-character S with distinguishing exponents, govern traflic movements over the stretch Y. Signals S and S govern eastbound traffic movements over stretch Y, that is, trafiic movements toward the right, as shown in the drawing. Signals S and S similarly govern westbound traffic movements over stretch Y. As shown in thedrawing, each ofthese signals is of the semaphore type.

Each of the signals-S and S operates a contact 12 which is closed when and only when the arm of the corresponding signal is in the stop position. Each of thesignals-S and S operates a contact 16 which is closed when the arm of the corresponding signal is.

nal repeater relays M and M, respectively. 1 V

Signal control relays H and'H are controlled in any suitable manner by either coded or non-coded current from a remote point such,cfor example, as a train despatchers N over a second line control wire I) and commonwireo.

Signals S and S may be controlled in any suitable manner. The controls forthese signals form no part of my present invention and are therefore not shown in the drawing. As shown in the drawing, all parts are in their normal condition, that is, the track sections are unoccupied, each relay Hland each relay N is deenergized, and each signal S is indicating stop- Since the track sections are unoccupied, each relay R is energized, and

relays T and T are therefore also energized. The circuit for relay T passes from terminal {81 of a source of current not shown;

R contact 5 of relay R contact 6 of relay R contact 7 of relay R and the winding of relay T to common wire 0 which is connected to the other terminal of the same source of" in the drawing, through contact 4 of relay 2 current. The circuit for relay T passes from terminal 00 of a second source ofcurrent not shown in the drawing, through contact 8 of relay R contact 9 of relay R contact 10 of relay R contact 11 of relay R, and the;

winding of relay T to common wire 0 which is also connected to the other terminal of the second source of current.

With the arm of signal S in the stop posi- I u I I tion, relay MP1s energized by a circuit pass-o ing from terminal 00, through contact i signal S and the winding of, relay M? to wire 0. With the arm of signal S? in the stop position, relay M is energized by. a, similar circuit which includes contact 12 of signal'Sfl I will now assume that the despatcher desires to permit an eastbound train to proceed over stretch Y. He will therefore cause relay H to become energized. Relay I-I upon becoming energized, closes its front contact 1411?, thereby completing a circuit for energizing relay H passing from terminal :2 through contact 13'=-13 of relay M wire a, Contact 14:14 of relay H contact 15 of relay T and winding of relay H to wire 0. Relay H upon becoming energized, completes, through its contact 19, anoperating circuit for signal S which causes the arm of signal S to move to its caution position.

15 When the arm of signal S leaves the stop position, contact 12 of signal S opens, causing relay M to become deenergized. Relay M upon becoming deenergized, completes a circuit for relay N if signal S is indicating either caution or proceed. "This circuit for relay N passes from terminal 00 through contact 16 of signal S contact 14"14 of relay H wire 6, contact 13'13 of relay M contact 17 of relay H contact 18 of relay H and the winding of relay N to wire 0. Relay N upon becoming energized, completes through its contact an operating circuit for causing the arm of signal S to move from the caution to the proceed position.

IVhen a train passes signal S deenergizing relay R the circuit for relay T becomes opened at contact 7 of relay R and hence relay T becomes deenergized. Relay T being deenergized, contact 15 of this relay opens the circuit for relay I-I Relay H being deenergized, contact 19 of this relay opens the circuit for operating the arm of signal S to the caution position, and contact 18 of this relay opens the circuit for relay N Contact 20 of relay N thereupon opens the circuit for operating the arm of signal S to the proceed position. The arm of sig nal S therefore now returns to the stop position. Relay T will remain deenergized until the train has passed through all the sections from B to F, and hence signal S will continue to indicate stop during this time.

The operation of the apparatus for westbound trafilc movements is'similar to that net described for eastbound traific movements. It will be noted that relay H upon becoming energized opens its back contact 1%114J in the circuit for relay N. It will also be noted that relay M upon becoming deenergized, opens its front contact 1313 in the circuit for relay H. It will be clear, therefore, that relay H cannot become energized as long as 60 relay M is deenergized, and that relay N cannotbecome energized as long as relay H isenergized. The arm of signal S can therefore not be operated to either the caution or the'proceed position as long as signal 65 S is indicating either caution or proceed.

Similarly, if the arm of signal S has been operated to the caution or proceed position, signal S cannot be operated to the caution or proceed position until the arm of signal S has been returned to the stop position.

From the foregoing description and the accompanying drawing, it is clear that, with apparatus embodying my invention, the inter-control of two opposing signals, such as signals S and S, is efiected'with the use of only two line control wires a and b and a common wire 0.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may bemade therein within the scope of the appended claims without departing from the spirit and scope of my invention. i 3

Having thus described my invention, what I claim is:

1. Incombination, a first and a second signal governing traffic movements in opposite directions over a given stretch of railway.- track, a signal repeater relay, a second signal repeater relay, means controlled by said first signal for energizing said first relay only when said first signal indicates stop, means controlled by said second signal for energizing said second relay only when said second signal indicates stop, a control relay for said first signal, a second control relay for said second signal, a circuit includinga' front contact of said first control relay and a front contact of said second repeater relay for 10 causing said first signal to display a caution indication, a second circuit including a front contact of said second control relay and a front contact of said'fir'strepeater relay for causing said second signal to display a caution indication, a third circuit including a back contact of said second control relay and a back contact of said first repeater relay for causing said first signal to display a proceed indication, and a fourth circuit including a back contact of said first control relay and a back contact of said second repeater relay for causing said second signal to display a proceed indication.

2. In combination, a first and a second signal governing traffic movements from a first and a second direction, respectively over a given stretch of railway track, a first and a second control wire and a common WlI'e,Cf means including said first control wire' and said common wire for controlling the caution indication of said first signal and the proceed indication'of said second signal, and means including said second control wire andssaid common wire for controlling the caution indication of said second signal and the proceed indication of said first signal.

3. In combination, a first and a second signal governing traffic movements from a firstc: and'a second direction respectively over a given stretch of railway track, a control wire, a second control wire, a circuit including said first control wire for-causing said first signal to display a caution indication, a second circuit including said second control wire for causing said second signal to display a cantion indication, a third circuit including said second control wire for causing said first signal to display a proceed indication, and a fourth circuit including said first control wire for causing said second signal to display a proceed indication.

4. In combination, a first and a second signal governing trafiic movements from a first and a second direction respectively over a given stretch of railway track, a signal repeater relay energized when said first signal indicates stop, a second signal repeater relay energized when said second signal -in-. dlcates stop, means controlled by a front contact of said first relay for controlling a caution indication of said second signal, means controlled by a back contact of said first relay for controlling a proceed indication of said first signal, means controlled by a front contact of said second relay, for controlling a caution indication of said first signal, and means controlled by a back contact of said second relay for controlling a proceed indication of said second signal.

5. In combination, a first and a second signal governing traflic movements from a first and a second direction respectively over a given stretch of railway track, a control relay for said first signal, a second control relay for said second signal, a circuit including a front contact of said first relay for controlling a caution indication of said first signal, a second circuit including a front contact of said second relay for controlling a caution indication of said second signal, a third circuit including a back contact of said first relay for controlling a proceed indication of said second signal, and a fourth circuit including a back contact of said second relay for controlling a proceed indication of said first signal.

In testimony whereof I aflix my signature.

RONALD A. McCANN. 

